RECIPROCAL NUMBER VALUE GENERATOR

摘要

PURPOSE:To obtain a reciprocal number value 1/A at the time in proportion to the logarithm value of the number of the bits of a necessary reciprocal number accuracy by generating an initial value X0 by an initial value circuit and obtaining a reciprocal number value Xn+1 at an arithmetic circuit based on the value X0 and a numeric value A. CONSTITUTION:An initial value circuit 2 calculates an initial value X0 of the reciprocal number for contents A of a register 1 and calculates the value X0 to a register 7. A multiplying circuit 3 multiplies the contents A of the register 1 and contents X0 of the register 7 and gives the result to a subtracting circuit 4. The subtracting circuit 4 subtracts multiplying results A.X0 from a constant value 2 and the result is supplied to a multiplying circuit 5. The multiplying circuit 5 multiplies a subtracting result (2-A.X0) and the contents X0 of the register 7 and a result X1 is stored into the register 7. The action is repeated until the value of the register 7 has the effective digits obtained. In addition, a reciprocal number value Xn+1(=1/A) of Xn+1=(2-A.Xn).Xn is outputted from the register 7.